Drip Coffee / Pour Over (1:17)
French Press (1:15)
Aeropress (Standard) (1:16)
Espresso (1:2)
Cold Brew Concentrate (1:10)
Custom Ratio
ml / grams
fl oz
Cups (6oz)
Your Brewing Recipe
Coffee Grounds Needed: 0 grams
Water Amount: 0 ml
Ratio Used: 1:17
The Science of Coffee-to-Water Ratios
The secret to a barista-quality cup of coffee isn't just the beans; it's the coffee-to-water ratio. This ratio determines the strength (TDS – Total Dissolved Solids) and the extraction level of your brew. Using a coffee brewing ratio calculator ensures consistency every time you boil the kettle.
What is the "Golden Ratio"?
The Specialty Coffee Association (SCA) recommends a "Golden Ratio" of 1:18. This means for every 1 gram of coffee, you use 18 grams of water. However, most coffee enthusiasts prefer a slightly stronger profile, often opting for 1:15 to 1:17 for drip and pour-over methods.
Method
Ratio
Grind Size
Flavor Profile
Espresso
1:2
Fine
Intense, concentrated
French Press
1:15
Coarse
Full-bodied, textured
Pour Over
1:16 – 1:17
Medium-Fine
Clean, bright, nuanced
Cold Brew
1:10
Extra Coarse
Smooth, low acidity
How to Use This Calculator
Select your method: Choose from presets like French Press or Espresso.
Input your water: Enter how much water you plan to use (or how many cups you want to make).
Get your results: The calculator will tell you exactly how many grams of coffee beans to weigh out.
Why Weight Matters More Than Volume
Measuring coffee by tablespoons is unreliable. Dark roasted beans are less dense and physically larger than light roasted beans. One tablespoon of dark roast might weigh 5 grams, while a tablespoon of light roast might weigh 7 grams. By using a scale and this calculator, you eliminate the guesswork.
function updateMethodRatio() {
var method = document.getElementById('brewMethod').value;
var customContainer = document.getElementById('customRatioContainer');
if (method === 'custom') {
customContainer.style.display = 'block';
} else {
customContainer.style.display = 'none';
}
}
function calculateCoffee() {
var waterInput = parseFloat(document.getElementById('waterAmount').value);
var unit = document.getElementById('waterUnit').value;
var method = document.getElementById('brewMethod').value;
var ratio;
if (isNaN(waterInput) || waterInput <= 0) {
alert("Please enter a valid water amount.");
return;
}
if (method === 'custom') {
ratio = parseFloat(document.getElementById('customRatio').value);
if (isNaN(ratio) || ratio <= 0) {
alert("Please enter a valid custom ratio.");
return;
}
} else {
ratio = parseFloat(method);
}
// Convert all water units to ml (1g water = 1ml)
var waterInMl;
if (unit === 'oz') {
waterInMl = waterInput * 29.5735;
} else if (unit === 'cups') {
waterInMl = waterInput * 177.441; // Standard 6oz coffee cup
} else {
waterInMl = waterInput;
}
var coffeeGrams = waterInMl / ratio;
// Update Results
document.getElementById('coffeeGrams').innerText = coffeeGrams.toFixed(1);
document.getElementById('waterFinal').innerText = Math.round(waterInMl);
document.getElementById('ratioDisplay').innerText = "1:" + ratio;
// Grind Advice
var advice = "";
if (ratio <= 3) {
advice = "Grind: Fine (Powder-like). Best for Espresso machines.";
} else if (ratio <= 12) {
advice = "Grind: Extra Coarse. Best for Cold Brew concentrate.";
} else if (ratio <= 15) {
advice = "Grind: Coarse (Like sea salt). Best for French Press.";
} else if (ratio <= 17) {
advice = "Grind: Medium. Best for Chemex, V60, or Auto-Drip.";
} else {
advice = "Grind: Medium-Fine. This is a very diluted ratio.";
}
document.getElementById('grindAdvice').innerText = advice;
// Show Result Area
document.getElementById('brewResult').style.display = 'block';
}